PossiblyNullOperand

An arithmetic or string operation is performed on a value that could be null. Passing null to most operators produces unexpected results or a warning at runtime.

Example

<?php
function divide(?int $a, int $b): float {
    return $a / $b; // $a could be null
}

How to fix

Guard against null before the operation:

<?php
function divide(?int $a, int $b): float {
    if ($a === null) {
        return 0.0;
    }
    return $a / $b;
}